I'm trying to set up a SSD of 75 GB as a cache for my 1TB mirror raid disc. During setup I can choose between a cache of 18.6GB or 64GB but whatever I choose I always end up with a remaining partition of 10GB, seems like it always picks 64GB. I'm using the latest version or IRST (10.8.0.1003). Anyone with a clue?

Could you please provide more detailed information on the hardware that is being used, like the model and manufacturer of the system, also specify what is the version of the option ROM that is installed.

Additionally, please include the system report that is generated by Intel(R) Rapid Storage Technology by using the instructions on the following site:

I would like to confirm that this normal, so the extra 10 GB is expected. Under “cache size” Intel(R) Rapid Storage Technology there are 2 choices “18.6GB" (which is the minimum size that can be allocated) and "Full disk capacity" (maximum 64 GB. Now, this will select a size that will be the full capacity of the SSD if its total capacity is less than 64GB. If its total capacity is over 64GB, the rest will be configured as the SSD Space volume for user data.

So, selecting 18.6 GB will actually end up not using the rest of the space available. In this case the system defaults to 64 GB to be able to still make the rest of the disk usable.

lightningchaser I'm having the same problem in my Dell Inspiron 7520. I deactivated the technologies for Linux installation and after reactivating Intel Smart Response in BIOS the Intel Smart Storage Software always fullfill the SSD with cache.

From factory defaults, my 32GB SSD was partitioned as 8GB of Hibernation partition (for intel rapid start) and the remaining space filled with caching. Now this partition scheme is not being possible.